1. Field of the Invention
The present invention relates to a liquid sprayer, and more particularly, to a multidirectional sprayer used in wet processes, such as cleaning, developing, and etching processes.
2. Description of the Prior Art
Liquid sprayers are used in a variety of wet semiconductor processes, such as cleaning, developing and etching processes. A prior art wet process liquid sprayer comprises a housing shell, a transport line for moving workpieces through the housing shell, and a spray system installed above the transport line in the housing shell.
The spray system comprises a plurality of parallel horizontal rocker pipes rotatably installed in the housing shell, each rocker pipe having a plurality of parallel nozzles directed in a generally downward direction. The spray system further includes driving and linkage devices to produce synchronized oscillation (rocking) of the rocker pipes so that all nozzles spray in the same direction at any given time. Due to continuing complexity and diversity of workpieces, such as plasma display panel (PDP) substrates, a liquid sprayer that has only one-direction nozzle aiming (rocking motion) becomes increasingly inefficient. Multidirectional nozzle aiming, therefore, improves process efficiency.
Please refer to FIG. 1 and FIG. 2. FIG. 1 is a side view of a prior art wet process liquid sprayer. FIG. 2 is a schematic diagram of a liquid supply system 20 and workpieces 34, 36. As shown in FIG. 1, the liquid sprayer 10 comprises a housing 12, the liquid supply system 20 used to transfer a liquid 26 onto the workpieces 34, 36. A transport line 30 is used to move and support the workpieces 34, 36 along a first horizontal direction, and a driving device (not shown) provides the spraying motion of the liquid sprayer 10. The liquid supply system 20 comprises a plurality of supply pipes 22 installed along a second horizontal direction, and a plurality of nozzles 24 mounted on the underside of the supply pipes 22. The transport line 30 comprises a plurality of rollers 32 to move the workpieces 34, 36 along the first horizontal direction in the housing 12.
The transport line 30 moves the workpieces 34, 36 along the first horizontal direction, which is perpendicular to the orientation of the supply pipes 22. Each supply pipe 22 is driven by the driving device and rotates in a reciprocating manner as indicated by the arrow 28 in FIG. 1. The nozzles 24 rotate with the supply pipes 22, and so the liquid 26 from the nozzles 24 is sprayed onto the workpieces 34, 36 in a reciprocating manner along the first horizontal direction.
The workpieces 34, 36 may be respectively the front and the rear glass plates of a plasma display panel. As shown in FIG. 2, the first workpiece 34 has parallel electrodes 35 that is parallel to the first horizontal direction. The second workpiece 36 has parallel electrodes 37 that is parallel to the second horizontal direction. The workpiece 34 moves into the housing 12 to be sprayed. Because the orientations of the parallel electrodes 35 and the motion of the nozzles 24 are both in the first horizontal direction, the residual chemical liquid on the workpiece 36 is easily washed away, making the chemical reaction more efficient. However, when the workpiece 36 moves into the housing 12, the orientation of the parallel electrodes 37 is perpendicular to the direction of the spraying motion of nozzles 24, and residual chemical liquid on the workpiece 36 is not easily washed away. Therefore, the workpiece 36 must remain in the spraying region for a longer period of time to ensure process completion. This increases both process time and the amount of chemical liquid used, which leads to higher process costs.
Furthermore, in the liquid sprayer 10, the supply pipe 22 is connected to the main pipe 21 with a sealing ring (not shown). The sealing ring is required as the supply pipes 22 rotate along the direction of the arrow 28, shown in FIG. 2. However, the sealing ring is not perfect, and the connections 23 between the supply pipes 22 and the main pipes 21 often have some leakage.
It is therefore a primary objective of the present invention to provide a multidirectional liquid sprayer to solve the above mentioned problems.
In a preferred embodiment, the present invention relates to a liquid sprayer comprising:
a housing comprising a hollow inner shell, and a transport line installed on a bottom portion of the inner shell for horizontally supporting a workpiece;
a plurality of transfer pipes vertically installed on an upper portion of the inner shell, and a nozzle installed at a lower end of each transfer pipe to spray a liquid in a downward direction;
a linking device fixed to the plurality of transfer pipes for moving the plurality of transfers pipe so that the nozzles are directed to spray in the same direction back and forth along different directions; and
a driving device fixed in the housing and used to drive the linking device in different directions so that the nozzles spray onto the workpiece in different directions with time.
It is an advantage of the present invention that the liquid sprayer drives the nozzles to spray in different directions, which improves the efficiency of the liquid sprayer.
This and further objectives of the present invention will become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment, which is illustrated in the various figures and drawings.